Most recent edition is (check Khanna Publishers). Older editions (3rd/4th) have fewer chapters on GIS/remote sensing but cover 90% of the core syllabus identically. An older used copy is fine for most exams.
While the temptation to get a free PDF is high, consider these issues: Most recent edition is (check Khanna Publishers)
: Detailed explanations of water loss due to infiltration, evaporation, and evapotranspiration before it becomes surface runoff. 2. Streamflow and Hydrograph Analysis Most recent edition is (check Khanna Publishers)
Amazon often carries the Kindle version of engineering textbooks. Search for “S.K. Garg Hydrology Kindle.” You can read it on any device via the free Kindle app. The price is typically 20-30% lower than the print version. Most recent edition is (check Khanna Publishers)
: Measurement techniques and analysis of rainfall data.